package lab02.test28;

import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        System.out.println("请输入要计算的圆的半径：");
        Scanner scanner=new Scanner(System.in);
        double a;
        try {
            a = scanner.nextDouble();
            System.out.println(a * a * 3.14);
        }catch (Exception e){
            System.out.println("对不起，您输入的数值无法计算");
        }
    }
}
